The diffusion-drift equation on comb-like structure

From the generalized scheme of random walks on the comb-like structure, one can obtain the fractional Fokker–Planck equation in the domain of fractal time evolution with critical exponent β (0<β 1). The operator method for the moments associated with the density p(x,t) is used to solve the obtained equation. It is shown that due to fingers diffusion has an anomalous character, the first two moments increase sub-linearly in time